Calendar indicator for time measuring systems

ABSTRACT

The invention concerns calendar devices for watches and clocks. In order to obtain a precise change in the date at midnight, three movable magnetized reference are fixed to the three spindles of the hours, minutes and seconds and three fixed magnetic sensors actuate the data indicator when their three respective signals coincide in time. The applications are in particular in the field of battery operated electronic watches.

United States Patent [191 Vovelle June 11, 1974 [54] CALENDAR INDICATOR FOR TIME 3.333.410 8/1 967 Barbella 58/4 R 3,361,973 I 1/1968 Wysong 58/33 X MEASURING SYSTEMS 3,456,123 7/1969 Pihl 340/309.4

Pierre G. Vovelle, Paris, France Thomson-CSF, Paris, France Feb. 6, 1973 Inventor:

Assignee:

Filed:

Appl. No.:

Foreign Application Priority Data Feb. 10, 1972 France 72.04507 US. Cl 58/4 A, 40/107, 58/58, v 58/85.5

Int. Cl. G04b 19/24 Field of Search .L...' 40/107; 58/4-6, 23 R, 33, 34, 38,50 R, 58, 85.5, 309.4; 340/325 Primary Examiner-Richard B. Wilkinson Assistant Eraminer.Edith Simmons Jackmon Attorney, Agent, or irm-Cushman, Darby & Cushman [5 7] ABSTRACT The invention concerns calendar devices for watches and clocks.

In order to obtain a precise change in the date at midnight, three movable magnetized reference are fixed to.the three spindles of the hours, minutes and 9 Claims, 4 Drawing Figures PATENTEDJUN 1 1 1914 3815351 SHEET 2 OF 2 24 POWER,

SUPPLY 2S SYSTEMS The present invention relates to the field of time pieces such as clocks and watches in which, in addition to information relating to the passage of time expressed in hours, minutes and possibly seconds, corresponding to the instant of observation, there are fumishedadditional indications as to the month and the day of the week, by a device known as a date indicator.

All of this information is shown on plane supports in the form of discs or articulated flaps by means of numbers and markings respectively in. the number of 31 for the months and? for the days of the week, the discs or flaps being shifted daily at around midnight a constant amount corresponding to one day, thereby displaying information in a fixed opening in such manner that. a single indication of each sort appearsat a time.

The mechanical energy required'for the daily changing of the date and day is usually taken, during the hours preceding the change, by a progressive winding of a spring, from the main drive mechanism on which it thus imposes temporarily a large additional load representing, in typical cases, a factor for the device displayingthe month and if that of the day of the week. is addedthereto. Such a variation in the drive torque in the course, of the 24 hours of a day, contrary to the known conditions of the isochronism of the oscillations of a balance, limits the precision that the hours mechanism alone would have afforded.

Another cause of the limitation of the precision resides in the necessity to modify the indication of the month according as the months have 30 or 31 days, which modification is achieved by manually turning in the suitable direction the hours and minute hands. At the end of this operation the precise indication of the time, so far ensured, is no longer maintained and requires resetting to the exact hour by comparison with an exterior reference timepiece.

Such conditions of use, permissible in the case of suing description, with'reference to the accompanying clocks and watches of ordinary structure cannot betolerated in electric and electronic clocks and watches employing a battery for the reasons given hereinafter-in respect of watches but also applicable to clocks:

First, from the operational point of view, the additional mechanical torque required by the actuation of a date indicator of known principle requires an increase in the size of the'motor and an increase in the amount of the associated source of electric energy which are totally incompatible with the available volume in a watchand/or with the cost of the periodical replacement of thebatteries constituting this source.

Further, as the choice of an improved design should be justified by improved performance as to precision, it is necessary, on one hand, to seek to achieve maxidoes not have the aforementioned drawbacks and satisfies the aforementionedconditions.

It comprises a daily actuating-devicefor a date indicator of anelectric or electronic watch, said watch 1 comprising a motion-work constituted by a train of the spindles of the seconds, the spindle of the minutes and the spindle of the hours at speeds of rotation respectively equal to l revolution per minute, 1 revolution per hour, and 2 revolutions per day, said device comprising movable reference elements the movement of which is controlled by said spindles, defining the angular positions of the reference elements with respect to fixed reference elements, each of said fixed reference elements being respectively subjected to an action produced by each of said movable reference elements upon their passage through a face-to-face position, each of said fixed reference elements producing under said action signals, said signals being applied to an electric control circuit controlling the display system of said date indicator, said circuit effecting said control only when said signals are simultaneous, and means inserted between said spindle of the hours and said display system for ensuring said actuation only every other revolution of said spindle of the hours.

The invention will be better understood from the endrawings, in which;

FIG. 1 represents a device according to the invention employing magnetic sensors or pick-up devices;

FIG. 2 represents a modification employing piezoelectric sensors or pick-up devices;

FIG. 3 represents another modification employing mechanical sensors or pick-up devices, and

FIG. 4 is an explanatory diagram.

FIG. 1 represents a date indicator device according to the invention applied to a time piece which indicates the hours, minutes and seconds, the mechanism of which comprises, in accordance with a known arrangement, a first spindle l of the seconds driving the hand 2 of the seconds by means of a motor 3, a second tubular spindle 4 of the minutes, disposed in coaxial relation to the seconds spindle 1 and carrying the hand 5 of the minutes and driven by the seconds spindle through a train of gear wheels 6, 7, 8, 9, which gear down at the speed ratio of 1/60 and a third tubular spindle 10 of the mum isochronism by ensuring for the hours mechanism I hours in coaxial relation to the minutes spindle 4 and driven by said spindle through the train of gear wheels 1'1, 12, 13, 14 effecting a gearing down at the speed ratio of one-twelfth and carrying the hand 15 of the hours. This structure will be hereinafter referred to under the name of motion-work.

According to first embodiment of the invention given by way of example, there is addedto the motion-work a train of gear wheels and 71 effecting a gearing down at the speed ratio of 1/2 and driving a spindle 72 at the speed of l-revolution per 24 hours.

Each of the three wheels 6, 9 and 71 respectively characterizes, by its angular position, measurable by the angular distance between fixed references or indexes and movable referencesor indexes carried by said spindles-orwheels, the time elapsed in 24 hours expressed in hours, minutes and seconds, namelyrespectively by one revolution per day, 1 revolution per hour and l revolution per minute.

The measurement of the angular differences is effected by respectively placing on each of said spindles a movable reference, integral with the spindles, and disposing in facing relation to said references three fixed elements constituting the forementioned fixed references and producing an electrical signal upon the passage of said movable references in front thereof.

In the case of FIG. 1 and in the embodiment given by way of example, the movable references or indexes are constituted by elements possessing a localized permanent magnetization, i.e. respectively one tooth of each one of the three gear wheels 6, 9 and 71, which teeth are indicated by the reference numbers 20, 21, 22 and the movable references are constituted by three magnetic sensors or pick-up devices 16, 17 and 18 disposed in facing relation to the peripheral part of the three gear wheels.

The signals which appear at the terminals of said sensors are sent to an electric circuit 19 of a type known per se which delivers an output signal only when there is simulteneous arrival at its input of the three signals produced by the passage of the movable magnetic references in front of the fixed magnetic sensors.

The setting of the relative angular positions of said movable references and the hands with which they are integral may be freely determined for any particular value of indication of the hours, minutes and. seconds. In'the described embodiment corresponding to one of the objects of the invention, the particular value of the chosen hour is midnight at which time indication the angular positions of the three hands coincide.

The output signal produced under these conditions by the circuit 19 determines the closure of a switch 23 inserted in a circuit comprising a source of voltage 24 and a drive element 25 which rotates through a constant angle, upon each switch closure, a disc 26 carrying the indications pertaining to the date numbers, only one of which appears at one time in a fixed opening 27 formed in the dial of the timepiece.

A push-button 40, connected in parallel with the switch 23 and accessible to the user, enables any desired date to be displayed at will either for an initial setting of the date'indicator or in the case of the months having less than 31 days in order to eliminate the days not needed. r

The date indicator must be actuated only once every 24 hours as mentioned hereinbefore, which explains the addition to the known motion-work for driving the spindles of the hours,'minutes' and seconds of an additional spindle 72 which revolves at the rate of l revolution per 24 hours and carries by a gear wheel 71 which is driven by a gear wheel 71.which effects a gearing down at the speed ratio of one-half. Indeed, in contradistinction to the spindles of the minutes and seconds which effect one revolution during the duration of time corresponding to the immediately higher unit of time, the spindle of the hours effects two revolutions per 24 hours, respectively corresponding to the passages at midday and midnight which renders it unsuitable, in the embodiment shown in FIG. I, for direct utilisation, as is the case of the spindles of the minutes and seconds, for the actuation of the date indicator. The train of wheels 70 and 71 thus effects by a mechanical means a division by two of the number of actuating signals coming from the hours spindle.

However, it is possible, without departing from the of 2 revolutionsper day, for actuating the date indicator which is in fact actuated only once per day.

To this end, the electronic circuit 19 comprises a known circuit arrangement to the input of which the bi-daily signal is fed and at the output of which is delivered only one signal every two signals, thereby effecting by electronic means a division by two of the number of daily actuating signals coming from the hours spindle.

FIG. 2 represents another embodiment of the invention in which the magnetic sensors shown in FIG. 1 are replaced by piezoelectric sensors.

The device, whose representation is limited to the elements which differ fr'om those shown inFIG. 1, comprises discs 60, 61, 62 integral with the spindles l, 4 and 10 and driven thereby, which discs perform the function of cams and carry the movable references the function of which has been explainedhereinbefore, in the form of localized'projections or lugs 80, 81, 82 disposed on their outer edge, each projection comprising an inclined leading portion and a rear portion perpendicular to said edge. The corresponding fixed referen ces are constituted by mechanical sensor or follower elements such as 66, 67, 68 which bear, on one hand, on said outer edge of each cam and, on the other hand, on piezoelectric elements 73, 75 and 75 which are connected to the inputs of the circuit 19 which produces an output signal for controlling the date indicator.

When the three discs are rotating, the projections 80, 81, 82 compress the piezoelectric elements 73, 74 and 75 and develop therein, in accordance with the known physical phenomenon, electric charges which are applied to the circuit 19.

When the projections in the course of the rotation o the discs, pass beyond the end of the sensors, the latter resume their initial position and the compression of the piezoelectric elements ceases.

The cessation of this compression is sudden whereas the initial compression is slow. By a suitable choice, in accordance with a practice familiar those skilled in the art, of the time constant of the input stages of the circuit 19, it is possible to obtain upon the cessation of the compression, a brief and definite electrical signal which may used for actuating the date indicator.

In the embodiment just described by way of example, mention was made of discs carrying projections on their periphery. However, it is possible to substitute therefore recessed steps by reversing the direction of the deformations.

FIG. 3 represents yet another embodiment of the invention in which the fixed references and movable references co-operate through mechanical means.

scope of the invention, to employ directly the spindle relating to the hours hand, which revolves at the speed The device the representation of which is limited to the elements which differ from those shown in FIG. 1, comprises discs 42, 43, 44 integral with the spindles 1, 4 and 10 and driven by the latter and carrying the aforementioned movable references in the form of recesses 45 formed on their outer edge and including a vertical leading flank and an inclined rear or trailing flank, and the fixed references are constituted by sensors, such as 46, which bear against said outer edge of of each disc and are capable of penetrating said reces ses and producing through control rods 47, the closure of switches 48, 49, 50 the necessity of which has already been mentioned for controlling the date indicator.

In the preceding embodiment given by way of example, description has been given of discs carrying recess es on their periphery. It is possible to substitute projecting portions or lugs for these recesses by reversing the direction of the movements of the lugs.

FIG. 4 is an explanatory diagram of the operation of the device according to the invention.

The coordinates represent horizontally the time and vertically the amplitudes of the signals produced by the three sensors, which may be amplitudes concerning magnitudes of electrical nature if the sensors are magnetic, or amplitudes of displacement concerning magnitudes of geometric nature if the sensors are mechanical.

The signals respectively corresponding to the hours, minutes and seconds, must overlap in order to guaran tee the desired simultaneousness, and if there is adopted, in a typical example of orders of magnitude, respective durations of signals oft-0.5 hour, i0.5 minute and t I second, consequently ensuring actuation of the date indicator to within a precision of i 1 second, there is obtained, with movable references carried by gear wheels effecting respectively 1 revolution per day, l revolution per hour and l revolution per second, a precision as to the respective angular positions of i 7,5 on the spindle of the hours, 3 on the spindle of the minutes, and i 6 on the spindle of the seconds, which orders of magnitude are quite possible in practice.

Of course the invention is not limited to the embodiments shown and described which were given solely by way of example. I

What is claimed is:

l. A device for actuating a date indicator in a watch comprising:

first means for independently driving in continuous motion seconds, minutes and hours hands in said watch, comprising a plurality of driving spindles, and a plurality of toothed wheels for actuating said spindles, rotating respectively at one revolution a minute, one revolution an hour and one revolution a day; second means for deriving electrical signals from said first means each time said toothed wheels have made a revolution; and coincidence means responsive to the simultaneous occurrence of said electrical signals for actuating said daily indicator.

2. A device as claimed in claim 1, wherein said second means comprise moving means solid with said toothed wheels for producing a reference signal defining wheels angular position, and reference signal pick up fixed means responsible to the moving past them of said moving means, and generating said electrical signals.

3. A device as'claimed in claim 2 wherein said mov-. ing means comprise magnetized elements.

4. A device as claimed in claim 2, wherein said moving means for producing a reference signal comprise cams solid with said toothed wheels.

5. A device as claimed in claim 4 wherein said reference signal pick up fixed means are piezoelectric elements said cams being arranged for exerting a pressure on said piezoelectric elements once per revolution.

6. A device as claimed in claim 4 wherein said reference signal pick up fixed means are switches controlled by said cams.

7. A devices as claimed in claim 1 wherein said coincidence means responsive to the simultaneous occurrence of said signals comprise a circuit which upon simultaneous occurrence of said electrical signals actuates a switch for closing a circuit comprising a source for actuating said day indicator.

8. A device as claimed in claim 7 comprising another separate switch for superseding the action of said switch and actuating said daily indicator for external control setting.

9. A device as claimed in claim 3, wherein said signal producing moving means comprise at least one magnetized tooth of said toothed wheels. 

1. A device for actuating a date indicator in a watch comprising: first means for independently driving in continuous motion seconds, minutes and hours hands in said watch, comprising a plurality of driving spindles, and a plurality of toothed wheels for actuating said spindles, rotating respectively at one revolution a minute, one revolution an hour and one revolution a day; second means for deriving electrical signals from said first means each time said toothed wheels have made a revolution; and coincidence means responsive to the simultaneous occurrence of said electrical signals for actuating said daily indicator.
 2. A device as claimed in claim 1, wherein said second means comprise moving means solid with said toothed wheels for producing a reference signal defining wheels angular position, and reference signal pick up fixed means responsible to the moving past them of said moving means, and generating said electrical signals.
 3. A device as claimed in claim 2 wherein said moving means comprise magnetized elements.
 4. A device as claimed in claim 2, wherein said moving means for producing a reference signal comprise cams solid with said toothed wheels.
 5. A device as claimed in claim 4 wherein said reference signal pick up fixed means are piezoelectric elements said cams being arranged for exerting a pressure on said piezoelectric elements once per revolution.
 6. A device as claimed in claim 4 wherein said reference signal pick up fixed means are switches controlled by said cams.
 7. A devices as claimed in claim 1 wherein said coincidence means responsive to the simultaneous occurrence of said signals comprise a circuit which upon simultaneous occurrence of said electrical signals actuates a switch for closing a circuit comprising a source for actuating said day indicator.
 8. A device as claimed in claim 7 comprising another separate switch for superseding the action of said switch and actuating said daily indicator for external control setting.
 9. A device as claimed in claim 3, wherein said signal producing moving means comprise at least one magnetized tooth of said toothed wheels. 